Thyroid function during the first year of recombinant human growth hormone therapy in short stature children

Area of Science:

• Pediatric Endocrinology
• Growth Hormone Therapy
• Thyroid Function Tests

Background:

• The impact of recombinant human growth hormone (rhGH) on thyroid function is debated, with theories suggesting it unmasks central hypothyroidism or induces subclinical primary hypothyroidism.
• Understanding these effects is crucial for monitoring children undergoing rhGH treatment.

Purpose of the Study:

• To evaluate thyroid function changes in children with short stature during their first year of rhGH treatment.
• To assess the correlation between these thyroid function alterations and growth velocity.

Main Methods:

• The study included 37 children receiving rhGH treatment, with 5 excluded due to side effects.
• Thyroid function (TSH, fT4) and growth parameters (height, height velocity) were monitored over the first year.

Main Results:

• A minor TSH increase and no significant fT4 change were observed in most groups within 3-6 months.
• Growth hormone deficiency (GHD) patients showed a significant fT4 decrease without TSH increase.
• Thyroid function normalized by the end of the first year; height velocities were similar across groups, except for GHD patients.

Conclusions:

• Transient subclinical primary hypothyroidism may be unmasked by rhGH therapy, indicated by slight TSH elevation and fT4 decrease.
• These temporary thyroid function changes do not adversely affect growth velocity in the initial year of rhGH treatment.